Return of Reckoning

Sometimes I see an auto attack after my first "casted" attack, sometimes I don't. Sometimes I'll stand still for five seconds doing nothing, sometimes I'll fire my bow or swing my sword. Do auto attacks fill in between casted abilities, or do I need to use the auto attack button? Does casting override auto attacks? Should I be weaving my abilities around auto attacking?

What class? SW or SH? I believe SW is tied to skirmish stance and both classes have an autoattack range.

Channels don't let you auto but your autos will fire off when the channel or build up is over. AA is also tied to your weapon it has a set speed. If a weapon has a speed of 2.4 it will auto attack every 2.4 seconds.